Fold flat seat assembly with rearward folding motion

ABSTRACT

A seat assembly is provided for supporting an occupant above a floor in an automotive vehicle. The seat assembly includes a seat cushion that is adapted to be pivotally coupled to the floor. The seat assembly also includes a seatback that is operatively coupled to the seat cushion for movement between an upright position and a folded position overlying the seat cushion. A linkage system is operatively coupled between the seatback, seat cushion, and the floor. The linkage system automatically moves the seat cushion downwards and forward and translates the seatback downward and rearward in response to movement of the seatback between the upright position and the folded position.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 12/516,838, which is a national phase application and claimsthe benefit, under 35 U.S.C. §371, of PCT/CA2007/002153, filed on Dec.3, 2007, which in turn claims the priority of United States ProvisionalApplication No. 60/872,325, filed on Dec. 1, 2006. All applications areincorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a seat assembly for an automotive vehicle. Moreparticularly, the invention relates to a seat assembly having a linkagesystem for automatically moving a seat cushion downward and forward andtranslating a seatback downward and rearward in response to pivoting theseatback between an upright position and a folded position.

2. Description of Related Art

Automotive vehicles include one or more seat assemblies for supportingseat occupants within a passenger compartment of the vehicle. Typically,seat assemblies include a generally horizontal seat cushion and agenerally vertical seatback. It is well known in the seating art toprovide a stowable seat assembly movable between a seating position forsupporting the seat occupant above the floor and a stowed position lyingflat against the floor, or nested within a recess formed in the floor.

In such stowable seat assemblies, the seatback is normally pivotallycoupled to the seat cushion at a seatback pivot located between a lowerend of the seatback and a rearward end of the seat cushion. The seatbackpivot allows the seatback to pivot between a generally upright positionand a folded position overlying the seat cushion. The seat cushion oftenincludes a four-bar-linkage or front and rear legs extending between theseat cushion and the floor of the vehicle for moving the seat cushionbetween a raised position spaced above the floor and a lowered positionresting along the floor. The seatback defines a load floor when the seatassembly is in the stowed position.

When such stowable seat assemblies are in a second or third row, behinda forward seat, an interference condition is often created when foldingthe seatback forward. Specifically, the seatback cannot pivot betweenthe upright position and the folded position without an upper end of theseatback contacting the forward seat. This interference condition ismagnified by federal motor vehicle safety standards, such as FMVSS 202a, which create high seatback height requirements. In addition, with theseatback pivotally coupled to the seat cushion at the seatback pivot,the load floor height is determined by the amount the seat cushion islowered toward the floor.

It is therefore desirable to provide a mechanism or linkage system whichlowers the seatback pivot such that the seatback is at a predeterminedload floor height when the seat assembly is in the stowed position. Itis also desirable that the linkage system translates the seatback pivotrearward such that the upper end of the seatback clears a forward seatas the seatback moves between the upright position and the foldedposition. It is further desirable that this motion be done whilelowering the seat cushion.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a seat assembly is providedfor supporting an occupant above a floor in an automotive vehicle. Theseat assembly includes a seat cushion that is adapted to be pivotallycoupled to the floor. The seat assembly also includes a seatback that isoperatively coupled to the seat cushion for movement between an uprightposition and a folded position overlying the seat cushion. A linkagesystem is operatively coupled between the seatback and the seat cushion.The linkage system automatically moves the seat cushion downward andforward and translates the seatback downward and rearward in response tomovement of the seatback between the upright position and the foldedposition.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings, wherein:

FIG. 1 is a side view of a seat assembly in a seating position includinga linkage system according to one embodiment of the invention;

FIG. 2 is a side view of the seat assembly in a first partially foldedstowed position;

FIG. 3 is side view of the seat assembly in a second partially foldedstowed position;

FIG. 4 is a side view of the seat assembly in a third partially foldedstowed position;

FIG. 5 is a side view of the seat assembly in a folded stowed position;

FIG. 6 is a side view of a seat assembly in a seating position includinga linkage system according to a second embodiment of the invention;

FIG. 7 is a side view of the seat assembly in a partially folded stowedposition;

FIG. 8 is a side view of the seat assembly in a folded stowed position;and

FIG. 9 is a partial perspective view of the second embodiment of theseat assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a seat assembly for an automotive vehicle isgenerally shown at 10. The seat assembly 10 includes a generallyhorizontal seat cushion 12 for supporting a seat occupant above a floor14 of the vehicle. The seat cushion 12 extends between a forward end 16and a rearward end 18. The seat assembly 10 also includes a seatback 20for supporting a back of the seat occupant. The seatback 20 extendsbetween a lower end 22 and an upper end 24. In the embodiment shown, ahead restraint 26 is operatively coupled to the upper end 24 of theseatback 20.

The seatback 20 is operatively coupled to the seat cushion 12 formovement between a generally upright position, as shown in FIG. 1, and afolded position overlying a seating surface of the seat cushion 12, asshown in FIG. 5. The seat assembly 10 is moveable between a seatingposition wherein the seatback 20 is in the upright position and the seatcushion 12 is in a raised position spaced above the floor 14, as shownin FIG. 1, and a folded stowed position wherein the seatback 20 is inthe folded position and the seat cushion 12 is in a lowered positionlying generally along the floor 14, as shown in FIG. 5.

In the embodiment shown, a forward riser 27 and a rearward riser 28 arefixedly secured to the floor 14 for mounting and supporting the seatassembly 10. It will be appreciated that in the alternative the seatassembly 10 may be directly mounted to the floor 14 without varying fromthe scope of the invention.

Referring to FIGS. 1 through 5, the seat assembly 10 includes a linkagesystem, generally shown at 30. The linkage system 30 automatically movesthe seat cushion 12 between the raised position and the lowered positionas the seatback 20 moves between the upright position and the foldedposition. More specifically, the linkage system 30 moves the seatcushion 12 from the raised position downward and forward to the loweredposition, and translates the seatback 20 downward and rearward as theseatback 20 moves from the upright position to the folded position. Itwill be appreciated that in the alternative the seat assembly 10 mayinclude a pair of spaced apart linkage systems 30 operatively coupled asdescribed in more detail below between the seatback 20, the seat cushion12, and the floor 14 without varying from the scope of the invention.Therefore, only one side of the seat assembly 10 having the linkagesystem 30 will be described in detail.

The linkage system 30 includes a seat cushion drive link 32, a frontlink 34, a rear link 36, and a seatback drive link 38. The seat cushiondrive link 32 is generally L-shaped and includes a first linear portion40 and a second linear portion 42. When the seat assembly 10 is in theseating position the first linear portion 40 of the seat cushion drivelink 32 is generally parallel with the seatback 20 and the second linearportion 42 is generally parallel with the seat cushion 12. The seatcushion drive link 32 extends between a first end 44 pivotally coupledto the lower end 22 of the seatback 20 and an opposite second end 46adjacent to the forward end 16 of the seat cushion 12. The second linearportion 42 is fixedly secured to the seat cushion 12.

The front link 34 is generally L-shaped and extends between a lower end48 and an upper end 52. The upper end 52 of the front link 34 ispivotally coupled to the second end 46 of the seat cushion drive link32. The lower end 48 of the front link 34 includes a distal end 50. Thelower end 48 is pivotally coupled to an apex of the forward riser 27.Although not shown, it is contemplated that a coil spring may bedisposed between the front link 34 and the forward riser 27 forassisting with moving the seat assembly 10 from the folded stowedposition to the seating position.

The rear link 36 is generally L-shaped and extends between a lower end54 and an upper end 56. The upper end 56 includes a distal end 58. Thedistal end 58 of the rear link 36 is pivotally coupled to the lower end22 of the seatback 20, below the pivotal connection between the firstend 44 of the seat cushion drive link 32 and the seatback 20. Thepivotal connection between the distal end 58 of the rear link 36 and thelower end 22 of the seatback 20 defines a seatback pivot axis A aboutwhich the seatback 20 pivots. The lower end 54 of the rear link 36 ispivotally coupled to an apex of the rearward riser 28.

The seatback drive link 38 extends between a first end 60 and a secondend 62. Preferably, the seatback drive link 38 has a curvature or bendbetween the first 60 and second 62 ends. The first end 60 of theseatback drive link 38 is pivotally coupled to the distal end 50 of thefront link 34. The second end 62 is pivotally coupled to the upper end56 of the rear link 36, between the lower 54 and distal 58 ends.

The seat assembly 10 further includes a latch mechanism (not shown), ofany suitable type commonly known in the art, for controlling themovement of the seat assembly 10 between the seating and stowedpositions. The latch mechanism is disposed between the distal end 58 ofthe rear link 36 and the lower end 22 of the seatback 20. The latchmechanism is operable between a locked state and an unlocked state byactuating a release handle (not shown). In the locked state, the latchmechanism maintains the seatback 20 in the upright position andtherefore prevents the seat assembly 10 from moving between the seatingand stowed positions. In the unlocked state, the latch mechanism isreleased to allow the seatback 20 to move between the upright positionand the folded position, thereby moving the seat assembly 10 between theseating and stowed positions. It will be appreciated that the latchmechanism may return to the locked state to maintain the seatback 20 inthe folded position. Although not shown, it is contemplated that theseat assembly 10 may include seat tracks to provide fore and aft seatadjustment, as is commonly known in the art.

In operation, starting with the seat assembly 10 in the seatingposition, as shown in FIG. 1, the release handle actuates the latchmechanism to the unlocked state to allow the seatback 20 to pivotforwardly about the seatback pivot axis A. The seat cushion drive link32 is driven forward by the forward pivotal movement of the seatback 20which in turn causes the front link 34 to pivot in a counterclockwisedirection about the lower end 48 (when viewed from FIGS. 2 through 4).As the front link 34 pivots in the counterclockwise direction, thedistal end 50 forces the seatback drive link 38 rearward, which in turncauses the rear link 36 to pivot in a clockwise direction about thelower end 54 (when viewed from FIGS. 2 through 4). The clockwisemovement of the rear link 36 translates the location of the seatbackpivot axis A downward and rearward until the seat assembly 10 is in thestowed position, as shown in FIG. 5. Thus, in response to movement ofthe seatback 20 from the upright position to the folded position, thelinkage system 30 automatically moves the seat cushion 12 downward andforward while translating the seatback 20 downward and rearward.

In the embodiment shown, the downward and rearward translation of theseatback pivot axis A allows the upper end 24 of the seatback 20, or inthis case the head restraint 26, to clear a forward seat, generallyindicated at 64, located in front of the stowable seat assembly 10. Itwill be appreciated that the stowable seat assembly 10 may be any seatwithin the vehicle without varying from the scope of the invention. Inaddition, the downward and rearward translation of the seatback pivotaxis A establishes a predetermined load floor height.

To return the seat assembly 10 to the seating position, the seatback 20is pivoted rearwardly about the seatback pivot axis A. The seat cushiondrive link 32 is driven rearward by the rearward pivotal movement of theseatback 20, which in turn causes the front link 34 to pivot in theclockwise direction about the lower end 48. As the front link 34 pivotsin the clockwise direction, the distal end 50 forces the seatback drivelink 38 forward, which in turn causes the rear link 36 to pivot in thecounterclockwise direction about the lower end 54. The counterclockwisemovement of the rear link 36 translates the location of the seatbackpivot axis A upward and forward until the seat assembly 10 is in theseating position, as shown in FIG. 1. Thus, in response to movement ofthe seatback 20 from the folded position to the upright position, thelinkage system 30 automatically moves the seat cushion 12 upward andrearward while translating the seatback 20 upward and forward.

Referring to FIGS. 6 through 9, wherein like primed reference numeralsrepresent similar elements as those described above, in a secondembodiment of the invention a seat assembly for an automotive vehicle isgenerally shown at 10′. The seat assembly 10′ includes a generallyhorizontal seat cushion 12′ for supporting a seat occupant above a floor14′ of the vehicle. The seat cushion 12′ extends between a forward end16′ and a rearward end 18′. The seat assembly 10′ also includes aseatback 20′ for supporting a back of the seat occupant. The seatback20′ extends between a lower end 22′ and an upper end 24′. In the secondembodiment shown, a head restraint 26′ is operatively coupled to theupper end 24′ of the seatback 20′.

The seatback 20′ is operatively coupled to the seat cushion 12′ formovement between a generally upright position, as shown in FIG. 6, and afolded position overlying a seating surface of the seat cushion 12′, asshown in FIG. 8. The seat assembly 10′ is moveable between a seatingposition wherein the seatback 20′ is in the upright position and theseat cushion 12′ is in a raised position spaced above the floor 14′, asshown in FIG. 6, and a folded stowed position wherein the seatback 20′is in the folded position and the seat cushion 12′ is in a loweredposition lying generally along the floor 14′, as shown in FIG. 8.

In the second embodiment shown, a forward riser 27′, a rearward riser28′, and a floor frame 29 are fixedly secured to the floor 14′ bybolting or any other suitable means for mounting and supporting the seatassembly 10′. The floor frame 29 extends vertically upwardly from thevehicle floor 14′ and extends horizontally from an end adjacent to theforward riser 27′ to an end adjacent to the rearward riser 28′. It willbe appreciated that in the alternative the seat assembly 10′ may bedirectly mounted to the floor 14′ without varying from the scope of theinvention.

The seat assembly 10′ includes a linkage system, generally shown at 70.The linkage system 70 automatically moves the seat cushion 12′ from araised position downward and forward to a lowered position, andtranslates the seatback 20′ downward and rearward as the seat back 20′moves from the upright position to the folded position. It will beappreciated that in the alternative the seat assembly 10′ may include apair of spaced apart linkage systems 70 operatively coupled as describedin more detail below between the seatback 20′, the seat cushion 12′, andthe floor 14′ without varying from the scope of the invention.Therefore, only one side of the seat assembly 10′ having the linkagesystem 70 will be described in detail.

The linkage system 70 includes a seat cushion drive link 72, a frontlink 74, a seatback link arm 75, a rear connector link 76, and aseatback drive link 78. The seat cushion drive link 72 is generallyL-shaped and includes a first portion 80 and a second linear portion 82.When the seat assembly 10′ is in the seating position, the first portion80 of the seat cushion drive link 72 is generally parallel with theseatback 20′ and the second linear portion 82 is generally parallel withthe seat cushion 12′. The seat cushion drive link 72 extends between afirst end 84 pivotally coupled to the link arm 75 and an opposite secondend 86. The second linear portion 82 of the seat cushion drive link 72is fixedly secured to the seat cushion 12′.

The front link 74 is generally linear and extends between a lower end 90and an upper end 92. The upper end 92 of the front link 74 is pivotallycoupled to the second end 86 of the seat cushion drive link 72. Thelower end 90 is pivotally coupled to an apex of the forward riser 27′.The pivotal connection between the lower end 90 of the front link 74 andthe apex of the forward riser 27′ defines a fixed pivot axis 88 aboutwhich the front link 74 pivots. Although not shown, it is contemplatedthat a coil spring may be disposed between the front link 74 and theforward riser 27′ for assisting with moving the seat assembly 10′ fromthe stowed position to the seating position.

The seatback link arm 75 is generally linear and extends between anupper end 83 fixedly coupled to the seatback 20′and an opposite lowerend 85 pivotally coupled to the rear connector link 76, as is furtherdescribed below.

The rear connector link 76 is generally triangular-shaped and includes afirst corner 173, a second corner 174, and a third corner 175. The firstcorner 173 is pivotally connected to the lower end 85 of the link arm75. The pivotal connection between the first corner 173 and the lowerend 85 of the link arm 75 defines a pivot axis A′ about which theseatback 20′ pivots. The third corner 175 is pivotally coupled to anapex of the rearward riser 28′. The pivotal connection between the thirdcorner 175 of the rear connector link 76 and the apex of the rearwardriser 28′ defines a fixed pivot axis B about which the rear connectorlink 76 pivots. A distal portion 179 extends from the rear connectorlink 76 adjacent to the third corner 175. The distal portion 179 ispivotally coupled to the seatback drive link 78 generally at a positionbelow the pivot axis B. The second corner 174 is opposite the thirdcorner 175.

The seatback drive link 78 extends between a first end 94 and a secondend 96. Preferably, the seatback drive link 78 has a curvature betweenthe first 94 and second 96 ends. The first end 94 of the seatback drivelink 78 is pivotally coupled to the front link 74 between the upper 92and lower 90 ends of the front link 74. The second end 96 is pivotallycoupled to the distal portion 179 of the rear connector link 76.

The seat assembly 10′ further includes a latch mechanism (not shown), ofany suitable type commonly known in the art, for controlling themovement of the seat assembly 10′ between the seating and stowedpositions. The latch mechanism is interconnected between the rearconnector link 76 and the link arm 75. The latch mechanism is operablebetween a locked state and an unlocked state by actuating a releasehandle (not shown). In the locked state, the latch mechanism maintainsthe seatback 20′ in the upright position and therefore prevents the seatassembly 10′ from moving between the seating and stowed positions. Inthe unlocked state, the latch mechanism is released to allow theseatback 20′ to move between the upright position and the foldedposition, thereby moving the seat assembly 10′ between the seating andstowed positions. It will be appreciated that the latch mechanism mayreturn to the locked state to maintain the seatback 20′ in the foldedposition.

In operation, starting with the seat assembly 10′ in the seatingposition, as shown in FIG. 6, the release handle actuates the latchmechanism to the unlocked state to allow the seatback 20′ to pivotforwardly about the pivot axis A′. The seat cushion drive link 72 isdriven forward by the forward pivotal movement of the seatback 20′,which in turn causes the front link 74 to pivot in a counterclockwisedirection about the pivot axis 88 (when viewed from FIGS. 6 through 7).As the seat cushion drive link 72 is driven forward and the front link74 pivots in the counterclockwise direction, the seat cushion 12′ istranslated forward and downward. In addition, as the front link 74pivots in the counterclockwise direction, the seatback drive link 78 isalso driven forward while pivoting about the pivotal connection betweenthe first 94 end of the seatback drive link 78 and the front link 74.The simultaneous forward movement of the seat cushion drive link 72 andthe seatback drive link 78 cause the rear connector link 76 to pivot ina clockwise direction about the pivot axis B while the link arm 75pivots in a counterclockwise direction about the pivot axis A′. Theclockwise movement of the rear connector link 76 translates the locationof the pivot axis A′ of the seatback link arm 75 downward and rearward.Since the link arm 75 is fixedly coupled to the seatback 20′, thedownward and rearward movement of pivot axis A′ translates the movementof the seatback downward and rearward and simultaneously translates theforward moving seat cushion 12′ further downward until the seat assembly10′ is in the folded stowed position, as shown in FIG. 8. Thus, inresponse to movement of the seatback 20′ from the upright position tothe folded position, the linkage system 70 automatically moves the seatcushion 12′ forward and downward while translating the seatback 20′downward and rearward.

In the second embodiment shown, the downward and rearward translation ofthe seatback 20′ allows the upper end 24′ of the seatback 20′, or inthis case the head restraint 26′, to clear a forward seat located infront of the stowable seat assembly 10′. It will be appreciated that thestowable seat assembly 10′ may be any seat within the vehicle withoutvarying from the scope of the invention. In addition, the forward anddownward translation of the seat cushion 12′ and the downward andrearward translation of the seatback 20′ establish a predetermined loadfloor height.

To return the seat assembly 10′ to the seating position from the foldedstowed position, the seatback 20′ is pivoted rearwardly about the pivotaxis A′. The seat cushion drive link 72 is driven rearward by therearward pivotal movement of the seatback 20′, which in turn causes thefront link 74 to pivot in the clockwise direction about the pivot axis88. As the seat cushion drive link 72 is driven rearward and the frontlink 74 pivots in the clockwise direction, the seat cushion 12′ istranslated rearward and upward. In addition, as the front link 74 pivotsin the clockwise direction, the seatback drive link 78 is also drivenrearward while pivoting about the pivotal connection between the first94 end of the seatback drive link 78 and the front link 74. Thesimultaneous rearward movement of the seat cushion drive link 72 and theseatback drive link 78 cause the rear connector link 76 to pivot in acounterclockwise direction about pivot axis B while the link arm 75pivots in a clockwise direction about the pivot axis A′. Thecounterclockwise movement of the rear connector link 76 translates thelocation of the seatback 20′ upward and forward and simultaneouslytranslates the rearward moving seat cushion 12′ further upward until theseat assembly 10′ is in the seating position, as shown in FIG. 6. Thus,in response to movement of the seatback 20′ from the folded position tothe upright position, the linkage system 70 automatically moves the seatcushion 12′ upward and rearward while translating the seatback 20′upward and forward.

The invention has been described here in an illustrative manner, and itis to be understood that the terminology used is intended to be in thenature of words of description rather than limitation. Manymodifications and variations of the present invention are possible inlight of the above teachings. It is, therefore, to be understood thatwithin the scope of the appended claims, the invention may be practicedother than as specifically enumerated within the description.

1. A seat assembly for supporting an occupant above a floor in anautomotive vehicle, said seat assembly comprising: a seat cushionadapted to be pivotally coupled to the floor for movement between araised position spaced above the floor and a lowered position lyingagainst the floor; a seatback operatively coupled to said seat cushionfor movement between an upright position and a folded position overlyingsaid seat cushion; and a linkage system operatively coupled between saidseatback and said seat cushion for automatically moving said seatcushion downward and forward and translating a lower portion of saidseatback downward and rearward in response to movement of said seatbackbetween said upright position and said folded position, said linkagesystem including a seatback link arm having an upper end fixedly securedto said seat back and an opposite lower end, a seat cushion drive linkextending between a first end pivotally coupled to said upper end ofsaid seatback link arm and a second end fixedly secured to said seatcushion, a front link extending between a lower end adapted to bepivotally coupled to the floor and an upper end pivotally coupled tosaid second end of said seat cushion drive link, a rear link connectorhaving a first portion pivotally coupled to said lower end of saidseatback link arm defining a seatback pivot axis, a second portionopposite said first portion, and a third portion between said first andsecond portion adapted to be pivotally coupled to the floor forproviding pivotal movement of said seat back between said uprightposition and said folded position, and a seatback drive link extendingbetween a first end pivotally coupled to said front link between saidupper and lower ends and a second end pivotally coupled to said secondportion of said rear link connector for pivoting said rear link aboutsaid third portion thereof and automatically translating said seatbackpivot axis downward and rearward in response to movement of said seatcushion from said raised position to said lowered position.
 2. A seatassembly as set forth in claim 1 wherein said pivotal connection betweensaid second end of said seat back drive link and said second portion ofsaid rear link connector is spaced below said third portion of said rearlink connector to assist the pivotal movement of said rear linkconnector in response to movement of said seat cushion between saidraised and lowered positions and the pivotal movement of said seatbackbetween said upright and folded positions.